Lower energy expenditure can’t get all the blame for today’s rising obesity levels, if study of hunter-gatherer population is correct.

Results from a new study* published in the July 25, 2012 issue of PLoS ONE reveal that there is no difference between the energy expenditure of modern hunter-gatherers and Westerners, challenging the widely accepted theory that today’s sedentary lifestyle in Western countries is the reason for rising obesity levels. The findings are also significant for understanding our relationship to our ancient hunter-gatherer past, as the study subjects are members of a modern-day hunter-gatherer population that is believed to closely reflect the way our ancient hunter-gatherer ancestors once lived.

Led by Herman Pontzer of Hunter College in New York City, along with David Raichlen of the University of Arizona and Brian M. Wood of Stanford University, the research team measured the daily energy expenditure (calories) of members of the Hadza, a population of hunter-gatherers who live in the open savannah of northern Tanzania. The Hadza, because of their life-style, are thought by scientists to closely approximate the way ancient hunter-gatherers in Africa may have lived tens of thousands of years ago in what many consider to be a possible ancestral homeland for modern humans. They found that, despite a way of life that involved trekking long distances to forage for wild plants and game, the Hadza actually did not burn more calories each day than modern-day adults in the U.S. and Europe. In their analysis, they tested for effects of body weight, body fat percentage, age, and gender. The study was significant in that it was the first to directly measure energy expenditure in hunter-gatherers; before, scientists had relied primarily upon estimates.

It is surprising because modern sedentary lifestyles characteristic of those living in Western countries are thought to be quite different from those of hunter-gatherers, and by extension our ancient hunter-gatherer ancestors. This fact is raised by many as the cause of the current rise in global obesity. Moreover, it challenges long-held assumptions that our ancient hunter-gatherer ancestors, always “on the go”, must have expended more energy than modern populations. It also suggests that metaboloc rates are actually comparatively constant among diverse human populations.

“These results highlight the complexity of energy expenditure,” says Pontzer . “It’s not simply a function of physical activity. Our metabolic rates may be more a reflection of our shared evolutionary past than our diverse modern lifestyles.”

Australian archaeologists are embarking on a study of one of the earliest ever records of a key transformation in human history: the end of the nomadic lifestyle.

The team, headed by Dr Andrew Fairbairn from the University of Queensland, will join with a British team next week to continue work on the excavation of a 10,000-year-old early village site in central Turkey.

The site, known as Boncuklu Höyük, is one of the earliest village sites found from the period when hunter-gatherer societies began to leave their nomadic lifestyle and take up farming.

Villagers lived in oval-shaped, mud brick houses and hunted, farmed and traded with other local communities on an area of wetlands which is now a dusty plain near the city of Konya.

“It’s come to be one of the key transformations in human history because, basically, the development of our civilisations is routed in a lot of these social and economic transformations that happened around about this time,” Dr Fairbairn told ABC News Online.

He says the site is one of the earliest found just outside the key Fertile Crescent area of eastern Turkey, Syria and Jordan where it is thought farming first originated.

The site is expected to help archaeologists understand how humans adapted to a sedentary lifestyle and how it spread across Europe.

“This farming lifestyle then spreads around the world – it goes across Europe and it goes across Asia,” Dr Fairbairn said.

“And so where Boncuklu is is that sort of first area where you have this spread of this new lifestyle.

“We’ve been very interested to find out whether it was, as it’s always been suspected, due to farming people moving from this area of origin, the Fertile Crescent … or whether it was due to the people who already lived there, lay hunter-gatherer societies, actually starting to develop and take up new crops and new ways of life.

“So Boncuklu is one of those very rare sites that allows us to investigate that time period.”

Boncuklu Höyük, which means “beady mound”, was discovered about a decade ago by the head of the British excavation team, Dr Douglas Baird, who had worked on the nearby, famous village site of Çatalhöyük.

Dr Fairbairn says Dr Baird was trying to place the excavation of Çatalhöyük in its regional context and, in typical archaeological fashion, found Boncuklu, which is 1,000 years older, on the last day of a field survey.

Named after the high number of stone and clay notched beads found in the mound, Boncuklu first underwent excavation in 2006.

Dr Fairbairn says Boncuklu has some things in common with Çatalhöyük, but in other ways it is more “alien”.

“It’s an interesting story because Çatalhöyük in a lot of ways is sort of bizarre,” he said.

“It’s different, but there’s something tangible and you can kind of understand it because of these rectangular houses and rooms and you can see fireplaces and things.

“Boncuklu is just a little bit more way out. It’s these funny little huts. For me it’s just something slightly more distant and a little bit more alien.

“It feels quite different. A little bit like you’re on a slightly different world.”

The excavation project will enter its second phase this year, after earlier developing and stabilising the site which was part of the local Turkish village.

Dr Fairbairn says the site will be expanded over the next two-and-a-half months with the help of about 50 students and professional archaeologists, about 30 of which will come from Australia.

He says a ring of huts on the mound are in the process of being unearthed, and archaeologists have found ash and bones in the centre of the huts, potentially signalling either a rubbish dump or meeting area.

Over the past year the team has discovered the skulls of wild cattle embedded into the wall plaster of huts, a tradition also carried out at Çatalhöyük.

The remains of plants foreign to the area that were used as crops have also been found on land near the site, Dr Fairbairn says.

“There’s some kind of use of crops but it seems to be quite small – it seems to be almost quite marginal in a lot of ways,” he said.

“What we have is, basically, a hunter-gatherer society there that is settling down, using some crops – importing them or trading them with other settlements.”

Connected communities

Dr Fairbairn says work done on human remains from the site has helped add to the understanding of how the village functioned and how it fit into its region.

“We have a sense now from some of the stable isotope work on the bones that this is a small community that lives in contact with other people and there seems to be some kind of movement,” he said.

“You can look at what people eat and use that to hypothesise where they’re coming from.

“What we tend to find is, in a lot of ancient communities, people have the same type of diet in one community, and what that leaves is a similar carbon and nitrogen isotope signal in their bones.

“You can look at the mix you actually have on your site and sort of see whether everyone is the same or whether you’ve got one person who is different.

“And what you tend to find in Boncuklu is a picture that we’re finding all the way across Europe now for this period, which is that all the men are the same and all the women are actually different.”

Dr Fairbairn says it appears men may have inherited land or were fixed in one place while women moved to different settlements.

Archaeologists in training

One of the students who will spend two months living onsite in Turkey is the University of Queensland’s Jessica Heidrich.

She says she expects the trip will provide valuable fieldwork experience which is essential for anyone pursuing a career in archaeology.

“I would be kicking myself if I didn’t take this opportunity even though I have to postpone my study and I have to save up a lot of money. It’s a site that most archaeologists would kill to go to,” she said.

“The contacts, hopefully, and opportunity for more fieldwork that will come out of it is what I’m really going for.”

Fellow UQ undergraduate Anna Florin went to the excavation site last year and says digging up an ancient civilisation requires a lot of patience.

“I spent most of my time in a trench where they’d already found a neolithic house that was subterraneal and we were taking away plaster layers on it and just getting an idea of how the house was constructed.

“So it was a lot of intricate work, peeling off one layer at a time.”

Dr Fairbairn says part of the second phase of the dig will be to develop more information about the site for the local Turkish community, as well as for tourists.

Native Americans of the desert Southwest subsisted on a diet that was much higher in fiber than our modern foods.

The findings come from analysis of ancient poop dating from A.D. 1125 and earlier.

The amount of fiber our diet contained in ancient times was up to sixteen times what we eat now.

The ancient Native Americans of the desert Southwest subsisted on a fiber-filled diet of prickly pear, yucca and flour ground from plant seeds, finds a new analysis of fossilized feces that may explain why modern Native Americans are so susceptible to Type II diabetes.

Thousands of years of incredibly fibrous foods, 20 to 30 times more fibrous than today’s typical diet, with low impact on the blood sugar likely left this group vulnerable to the illness when richer Anglo foods made their way to North America, said study researcher Karl Reinhard, a professor of forensic sciences at the University of Nebraska-Lincoln.

“When we look at Native American dietary change within the 20th century, the more ancient traditions disappeared.” Reinhard told LiveScience. “They were introduced to a whole new spectrum of foods like fry-bread, which has got a super-high glycemic index.”

The glycemic index of a food is a measure of how fast its energy is absorbed into the bloodstream. It’s measured on a scale of 1 to 100, with 1 being the slowest absorbing with the least effect on blood sugar. The native people who lived in the deserts of Arizona would have likely eaten traditional stews with glycemic indexes around 23, Reinhard found. Foods scoring lower than 55 are considered “low-GI” foods.

Modern food and modern disease

Members of Southwest Native American tribes are more susceptible than Caucasians to Type II diabetes, which happens when the body either doesn’t produce enough insulin to break down sugar from food, or when the body’s cells fail to recognize the insulin it does produce.

Researchers have long hypothesized that a “thrifty gene” (or, more likely, genes) acquired through feast and famine makes Native American populations more prone to this chronic disease. The idea is that people who were able to rapidly adapt to both lean times and times of plenty would have done better in ancient times. Today, the modern diet has rendered famine rare in the developed world, but the body continues to respond to times of plenty as if starvation is around the corner. Diabetes and obesity can result.

Reinhard and his colleagues now suggest that feast and famine may not be necessary for the “thrifty gene” hypothesis to make sense. Basically, Reinhard said, an extremely low-calorie, high-fiber diet made the ancient Native American gut a paragon of efficiency. With the arrival of whites, the diet changed faster than physiology could keep up with it. In other words, the digestive system didn’t evolve for abundant, high-GI foods.

High-fiber diet

To find solid evidence of what ancient Southwestern tribes actually ate, Reinhard turned to what he called “the most intimate residues from archaeological sites” — fossilized poop. Known as coprolites, these fossils contain a record of their creator’s most recent meals.

The researchers analyzed 25 coprolites from Antelope Cave in northwestern Arizona, a dwelling that was seasonally occupied for thousands of years. These particular coprolites (20 of which turned out to be human) date back to at least A.D. 1150 and earlier. The dates make the cave a perfect time to look at the transition from a total hunter-gatherer lifestyle to one supplemented by some agriculture, Reinhard said.

“It bridges two different dietary traditions, one which has been around for several thousands of years with one that was relatively newly introduced at the time the cave was occupied,” he said.

The analysis revealed that these ancient people chowed down on flour made from maize and wild sunflower and other seeds, as well as on fibrous succulent plants such as yucca and prickly pear. This diet was higher fiber than anything modern people eat. The feces were three-quarters fiber by volume, Reinhard said, and these Native Americans were probably eating between 200 and 400 grams of the indigestible stuff per day. For comparison, the Institute of Medicine recommends 25 grams of fiber a day for the modern woman, and 38 grams for men. The average adult manages only about 15 grams.

Modern agriculture has favored plants with less fiber, Reinhard said, so even the ancient tribes’ maize would have been more fibrous than the corn we eat today.

“When I was a young researcher I tried to replicate this diet, and it was impossible,” Reinhard said. “I was essentially eating all day to try to get this fiber.”

Evolving diets

In addition, Reinhard and his colleagues reported in the August issue of the journal Current Anthropology, the Southwest Native American diet had a very low glycemic index. Prickly pear pads, a common staple, rate only a 7 on the 100-point GI scale. The highest-GI food these tribes would have had was maize, the researchers found, which would fall at about 57 on the scale — just two points shy of qualifying as a “low-GI” food today. (Modern sweet corn on the cob has a GI of 60; processed foods like white rice and bagels are in the 90-95 range.)

In addition, prickly pear has a known blood-sugar-lowering effect, Reinhard said. Agave and yucca plants would have also had minimal effect on the blood sugar while providing yet more fiber. Rabbit, including bone fragments, was also found in the fecal fossils.

“The change we have undergone over generations has been toward less appreciation of really resistant foods and more toward what is called a ‘Pablum’ diet,” Reinhard said. “It’s kind of like going from chewing on pumpkin seeds to chewing on oatmeal.”

The diet seen in the desert Southwest up to just 1,000 years ago is likely similar to what people ate the whole world over up until about 15,000 years ago, Reinhard said. And then humans invented agriculture, cultivating wheat, millet, rice and other grains.

“These plants, as they were cultivated, replaced the really, really ancient foods that everybody ate thousands and thousands of years ago with calorie-dense foods, or grains that could be turned into calorie-dense foods like grains, rice cakes, and, of course, alcoholic beverages,” Reinhard said.

Professor Mike Fulford at the dig in Silchester. The latest find is an olive stone that dates back to Iron Age Britain. Photograph: Graham Turner for the Guardian

Topic:Ancient pizza

Iron Age Britons were importing olives from the Mediterranean a century before the Romans arrived with their exotic tastes in food, say archaeologists who have discovered a single olive stone from an excavation of an Iron Age well at at Silchester in Hampshire.

The stone came from a layer securely dated to the first century BC, making it the earliest ever found in Britain – but since nobody ever went to the trouble of importing one olive, there must be more, rotted beyond recognition or still buried.

The stone, combined with earlier finds of seasoning herbs such as coriander, dill and celery, all previously believed to have arrived with the Romans, suggests a diet at Silchester that would be familiar in any high street pizza restaurant.

The excavators, led by Professor Mike Fulford of Reading University, also found another more poignant luxury import: the skeleton of a tiny dog, no bigger than a modern toy poodle, carefully buried, curled up as if in sleep. However it may not have met a peaceful end.

“It was fully grown, two or three years old, and thankfully showed no signs of butchery, so it wasn’t a luxury food or killed for its fur,” Fulford said. “But it was found in the foundations of a very big house we are still uncovering – 50 metres long at least – so we believe it may turn out to be the biggest Iron Age building in Britain, which must have belonged to a chief or a sub chief, a very big cheese in the town. And whether this little dog conveniently died just at the right time to be popped into the foundations, or whether it was killed as a high status offering, we cannot tell.

“The survival of the olive stone, which was partly charred, was a freak of preservation. But there must be more; we need to dig a lot more wells.”

Fulford has been leading the annual summer excavations at Silchester, which bring together hundreds of student, volunteer and professional archaeologists, for half a lifetime, and the site continues to throw up surprises. It was an important Roman town, but deliberately abandoned in the 7th century, its wells blocked up and its buildings tumbled, and never reoccupied. Apart from a few Victorian farm buildings, it is still open farmland, surrounded by the jagged remains of massive Roman walls.

Fulford now believes that the town was at its height a century before the Roman invasion in 43AD, with regularly planned, paved streets, drainage, shops, houses and workshops, trading across the continent for luxury imports of food, household goods and jewellery, enjoying a lifestyle in Britain that, previously, was believed to have arrived with the Romans.

This sodden summer have driven the archaeologists to despair, with the site a swamp of deep mud and water bubbling up in every hole and trench.

“Conditions are the worst I can ever remember. Ironically, the wells are the easiest to work in because we have the pumps running there,” Fulford said.

The tiny dog is one of dozens that the team has excavated here over the years, including one that was buried standing up as if on guard for 2,000 years. A unique knife with a startlingly realistic carving of two dogs mating was another of the spectacular finds from one of the most enigmatic sites in the country.

Visitors can observe the archaeologists’ trench warfare this weekend, when the site opens to the public as part of the national festival of archaeology, one of thousands of events across the country.

Original article:
By Maev Kennedy
Thursday July 19, 2012guardian.co.uk

An international team of researchers, led by the Universitat Autònoma de Barcelona and the University of York, has provided the first molecular evidence that Neanderthals not only ate a range of cooked plant foods, but also understood its nutritional and medicinal qualities.
Until recently Neanderthals, who disappeared between 30,000 and 24,000 years ago, were thought to be predominantly meat-eaters. However, evidence of dietary breadth is growing as more sophisticated analyses are undertaken.

Researchers from Spain, the UK and Australia combined pyrolysis gas-chromatography-mass spectrometry with morphological analysis of plant microfossils to identify material trapped in dental calculus (calcified dental plaque) from five Neanderthals from the north Spanish site of El Sidrón.

Their results, published in Naturwissenschaften – The Science of Nature* this week, provide another twist to the story – the first molecular evidence for medicinal plants being used by a Neanderthal individual.

The researchers say the starch granules and carbohydrate markers in the samples, plus evidence for plant compounds such as azulenes and coumarins, as well as possible evidence for nuts, grasses and even green vegetables, argue for a broader use of ingested plants than is often suggested by stable isotope analysis.

Lead author Karen Hardy, a Catalan Institute of Research and Advanced Studies (ICREA) Research Professor at the Universitat Autònoma de Barcelona (UAB) and an Honorary Research Associate at the University of York, UK, said: “The varied use of plants we identified suggests that the Neanderthal occupants of El Sidrón had a sophisticated knowledge of their natural surroundings which included the ability to select and use certain plants for their nutritional value and for self-medication. While meat was clearly important, our research points to an even more complex diet than has previously been supposed.”
Earlier research by members of this team had shown that the Neanderthals in El Sidrón had the bitter taste perception gene. Now trapped within dental calculus researchers found molecular evidence that one individual had eaten bitter tasting plants.

Dr Stephen Buckley, a Research Fellow at the University of York’s BioArCh research facility, said: “The evidence indicating this individual was eating bitter-tasting plants such as yarrow and camomile with little nutritional value is surprising. We know that Neanderthals would find these plants bitter, so it is likely these plants must have been selected for reasons other than taste.”

Ten samples of dental calculus from five Neanderthals were selected for this study. The researchers used thermal desorption and pyrolysis gas-chromatography-mass spectrometry to identify both free/unbound and bound/polymeric organic components in the dental calculus. By using this method in conjunction with the extraction and analysis of plant microfossils, they found chemical evidence consistent with wood-fire smoke, a range of cooked starchy foods, two plants known today for their medicinal qualities, and bitumen or oil shale trapped in the dental calculus.

Professor Matthew Collins, who heads the BioArCh research facility at York, said: “Using mass spectrometry, we were able to identify the building blocks of carbohydrates in the calculus of two adults, one individual in particular having apparently eaten several different carbohydrate-rich foods. Combined with the microscopic analysis it also demonstrates how dental calculus can provide a rich source of information.”

The researchers say evidence for cooked carbohydrates is confirmed by both the cracked/roasted starch granules observed microscopically and the molecular evidence for cooking and exposure to wood smoke or smoked food in the form of a range of chemical markers including methyl esters, phenols, and polynuclear aromatic hydrocarbons found in dental calculus.

Professor Les Copeland from the Faculty of Agriculture and Environment, University of Sydney, Australia, said: “Our research confirms the varied and selective use of plants by Neanderthals.”

The study also provides evidence that the starch granules reported from El Sidrón represent the oldest granules ever to be confirmed using a biochemical test, while ancient bacteria found embedded in the calculus offers the potential for future studies in oral health.

The archaeological cave site of El Sidrón, located in the Asturias region of northern Spain, contains the best collection of Neanderthal remains found in the Iberian Peninsula and one of the most important active sites in the world. Discovered in 1994, it contains around 2,000 skeletal remains of at least 13 individuals dating back around 47,300 to 50,600 years.

Archaeological and biological studies carried out since the year 2000 have contributed greatly to the knowledge of Neanderthals and how they lived.

Among the most important contributions is the identification of three Neanderthal genes: FOXP2, related to speech capacity; MCR1, related to pigmentation; and TAS2R38, related to the perception of bitter taste. The results of these studies have been incorporated into the macro project of the Neanderthal Genome and are being used in various genetic studies conducted in collaboration with the Max Planck Institute of Germany.

Antonio Rosas, of the Museum of Natural History in Madrid – CSIC (Spanish National Research Council), said: “El Sidrón has allowed us to banish many of the preconceptions we had of Neanderthals. Thanks to previous studies, we know that they looked after the sick, buried their dead and decorated their bodies. Now another dimension has been added relating to their diet and self-medication.”
Fieldwork at El Sidrón, conducted by researchers from the University of Oviedo, is funded by the Department of Culture, Principality of Asturias. The dental calculus samples used in this study were provided by the laboratory leading the study of the human remains discovered in El Sidrón, which is located at the Museum of Natural History in Madrid – CSIC.